ECONOMIC CONSIDERATION OF ELECTRICITY

WHICH FACTORS EFFECT THE ECONOMY OF ELECTRICITY?

The given below factors effect the power plant economy:

1.Electrical demand factor: It is the ratio of the maximum demand on a power system to the connected load on a power system by the consumer.

D.F. = Maximum demand / Connected load < 1

The value of the electrical demand factor is always less than one. Because the value of connected load is always greater than maximum demand.

Significance of demand factor: The significance of demand factor is given below:

• Capacity of the power generating station can be determined with the help of demand factor.
• With the help of demand factor, the cost and capacity of the equipment installed at the power generating station can be determined.

→In simple words, we can say that the electric demand factor shows the capacity of power generating stations. Because the electrical demand factor is the ratio of the maximum demand and the connector load. This gives us an idea of ​​what the maximum demand will be at the generating station and thus we know the capacity of the power generating station.

2.Electric load factor: It is the ratio of average electric load to the maximum electric load.

E.L.F. = Average load / Maximum load <1

The value of electric load factor is always less than one. Because the value of maximum demand is always greater than average electric load.

Significance of load factor: We know that the capacity of the power generating station depends on the maximum demand. Thus if our average load and maximum demand will be the same, then the per unit value of generated electricity decreases. Because the generated electricity is almost equal to consumed electricity.

In other words, we can say that the value per unit of electricity decreases with the increase in the value of electric load factor and the value per unit increases with the decrease of electric load factor.

The value of the ideal load factor is unity, which is not possible.

3.Connected Electric Load factor: It is the ratio of the average load and the connected electric load on a given power system.This is expressed as follows:

C.L.F. = Average load / Connected load < 1

OR

C.L.F. = Load factor * Demand factor

The value of the connected electric load factor is always less than one. Because we know that the connected electric load factor is the ratio of the average load and the combined load and the value of the combined load is greater than the average load.significance of the connected load factor: The Significance of the connected electric load factor: We know that both the connected electric load and the load factor are directly proportional to the average load. Therefore, the significance of both

factor is the same.

Means if the value of the connected load factor increases then the value per unit of electricity decreases and if the value of the connected load factor decreases then the value per unit of electricity increases.

4.Diversity factor: It is the ratio of sum of individual maximum demand of different consumers and the maximum demand of entire group on the power supply system. This is expressed as follows:

D.F. = Sum of individual maximum demand / Maximum demand of entire group > 1

Example: Let maximum demand of different consumers at different times are given as:

Consumer A = 1 MW at 12:00 (time)

Consumer B = 3 MW at 14:00

Consumer C = 5 MW at 16:00

Consumer D = 7 MW at 15:00

Maximum demand of the substation / generating station : 10 MW

So, according to diversity factor formula:

D.F. = 1 + 3 + 5 + 7 / 10

= 1.5 > 1

The value of the diversity coefficient is always greater than one. Because we know that the individual highest demand is more than the maximum demand of entire group.

Significance of Diversity factor: We know that the capacity of a power generating station depends on its maximum demand. Therefore, if the value of the diversity factor is high (because at this time the value of the maximum demand of entire group will be lower, So the maximum demand or capacity of the power generating center will be less). Then the construction of a small power generation station will be required and the capital cost will be less. Thus decreases the value of per unit electricity.

Conclusion: These factors affect the generating cost of per unit electricity. So the knowledge of these factor is very necessary at the time of construction of power plant. The proper knowledge of these factor reduces the per unit cost of generated electricity.

ELECTRIC LOAD CURVE

WHAT IS ELECTRIC LOAD CURVE AND TERMS RELATED TO IT?

Electric load curve: The electric load at the power stations varies with time, So a curve is drawn between the electric load and the time to find the variable electric load at a power station in time. This curve is known as electric load curve.

At the time of drawing the electric load curve, the electric load is displays on the vertical axis (y-axis) and the time on the horizontal axis (x-axis).

According to time the electric load curve has following three types:

1.Daily electric load curve: This curve is drawn between daily (24 hours) load and time (24 hours). This curve helps to find daily average load.

2.Monthly electric load curve: This curve is drawn between monthly (per days load) load and time (monthly). With the help of daily average load curve, we can draw monthly average electric load curve.

3.Yearly electric load curve: This curve is drawn between yearly (per month loads) and time (yearly). With the help of monthly average load curve, we can draw yearly average electric load curve.

Advantages of electric load curve:

• 

  Electric load curve (Daily)

  With the help of this curve we can find the electric load at different time.
  
• With the help of electric load, we can find the values ​​of peak electric load, mean electric load and minimum electric load at generating stations or sub - substations.
• From this curve, the value of the production or expenditure of the entire electrical energy for a given time is known.
•  From this curve, the ratio of the average electric load and the highest electric load is known, which is known as electric load factor.

Different term related to electric load curve:

1.Electric load: The electric equipment like bulb, tube light, machines etc are connected to electric system is known as electric load.

Its unit is KW or KVA.

Different types of electric load is given below:

• Variable electric load: If the load on electric system changes with time than this type of load is known as variable electric load.
• Constant electric load: If the load on electric system does not change with time, than this type of load is known as constant electric load.
• Base electric load: A certain amount of minimum electric load that always available on a power plant is called base electric load.
• Peak electric load: The highest value of variable load is called peak electric load. The peak load is shown in the electric load curve. With the help of this value, we determine the capacity of the plant. The peak electric load duration is at least 30 minutes.
• Minimum electric load: A low value of variable electric load is called a minimum electric load. This affects the capacity of the base load plant. Its duration is at least 30 minutes.
• Average electric load: It is the ratio of total electrical energy produced to the time. Its unit is watts or kilowatts. It is mainly expressed with time such as daily, monthly and annual average electric load etc.

A.E.L = Produce electric energy / time

Daily A.E.L. = Daily produce electric energy / 24

Monthly A.E.L. = Monthly produce electric energy / 30*24

Yearly A.E.L. = Yearly produce electrical energy / 365*24

Average electric load from load curve:

A.E.L. = Area of electric load / Base of electric load

Peak electric load > Average electric load > Minimum electric load

2.Connected Electric Load: The sum of the ratings of different types of electric equipment connected to the power supply system is called connected electric load.

For example: A house is equipped with a 60 watt fan, 1050 watt AC, two 20 watt tube lights, and a 100 watt refrigerator, then we can find the connected load by summing the ratings of all these equipment.

Connected electric load = 60 + 1050 + 40 + 100

= 1250 Watt

3.Demand: The demand of electric power of electric consumers is called demand. Its unit is watt, kilowatt or kilo-volt ampere.

4.Maximum Demand: When all connected loads are run for a certain interval of time, then adding the rating of all the equipment at this time will be called maximum demand for the power system.

→This interval of time may be in hours, a day, a month etc.

Conclusion: Electric load curve is very useful curve that gives different type of data like energy consume, energy produce, maximum demand of system, average load of electric system etc. So, it is necessary to draw load curve in every electric system where large amount of energy generate or consume like generation station, sub - station, factory etc.

RENEWABLE ENERGY SOURCES

WHAT IS RENEWABLE ENERGY AND ITS SOURCES?

Renewable energy: Renewable energy are those sources of energy that are available in unlimited quantities and we continuously use them.

OR

Energy sources that can be recycled are called renewable energy sources.

Advantages of renewable energy sources are given below:

• There is no pollution by using this type of energy.
• These are available in unlimited quantities. 
• There are unlimited resources available for renewable energy. 
• The cost of renewal energy is less as compared to other types of energy. 
• Renewable energy is environment friendly.

Different types of solar energy is given below:

1.Solar energy

2.Hydro energy

3.Wind energy

4.Bio-gas

5.Bio-diesel

6.Geothermal energy

7.Ocean energy

8.Biomass energy

Solar Energy

Solar energy: Solar energy is a source of renewable energy. Due to nuclear fusion in the sun, a large amount of energy is released from sun in the form of photons.

As indicated by the equation given below, we can understand the energy produced in the sun.

2 H + 2 H → He + 2 n + Heat Energy

Thus by above reaction we see that four hydrogen atom (lighter atom) combine to form a helium atom (heavier atom) and produced large amount of heat.

The heat energy released from the sun reaches the Earth in the form of radiations (photons). These radiations are stored by charging the battery through a solar panel and thus we use solar energy as electrical energy.

The other use of solar energy is given below:

1.Solar cooker

2.It provides energy to satellites

3.Solar cell

4.Solar battery

5.Solar water heater

6.Solar light etc.

→There is no transport expense as the transfer of energy is done by radiation.

→Worlds largest solar plant is situated in India (Kamuthi in the district of Ramnathpuram Tamil Nadu).

Dam

2.Hydro energy: Hydro energy also comes under renewable energy sources. Because it is a source of non-conventional energy. 

A hydro power project is a method by which electric energy is produced by the use of hydro energy. In this method, dams are built on the rivers and the turbine is rotated by dropping the water (by use of kinetic energy of water) collected in the dam from a height. In this way the turbine rotates to generate electricity.

The water released by this method is used in many types of works such as irrigation, fisheries, tourism etc. Hence this project is also called a multi-purpose project.

Now these days many types of micro water projects in India generate electric energy. According to their production capacity they can be classified as follows:

• Micro hydro project : 0 - 100 kilowatt
• Mini hydro project : 1 - 2 Megawatt
• Small hydro project : 2 - 2.5 Megawatt

In India, Arunachal Pradesh, Jammu and Kashmir, Uttarakhand, Himachal Pradesh, Punjab, Haryana, Uttar Pradesh are the leading states in the implementation of Micro and Small Hydro Scheme. In addition Nepal, Bhutan and Indonesia are also implementing this scheme.

Wind Mill

3.Wind energy: It is a renewable energy source. To generate electricity from wind power, large wings
are mounted at some height and due to flow of wind these fans rotate and the rotation of these wings rotates the shaft of the alternator and generates electric energy.Thus we use it to generate electrical energy.

To generate electric energy from wind energy, the ideal speed of wind must be continuous at 23 meters per second. 

In addition, wind energy is also used for drawing water, grinding flour etc.

Bio-gas Plant

4.Bio-gas: Various types of animal faeces, feed, peels of vegetables or fruits and other household waste are collected in an underground trough and when the trough is filled, pour water over it and cover it. A pipe is put above the trough to collect the gas produced in the trough. The remaining material in the pit is organic manure and it is called compost.These days it is produced at both domestic and commercial levels. At the commercial level, this gas is produced in a bio-gas plant.

Jatropha Curcas leaf

5.Bio-diesel: The diesel derived from organic sources is called bio-diesel. Bio-diesel is produced from Jatropha
curcas, sunflower, rapeseeds, palm, karanj etc. Bio-diesel produced from these plants can operate with the same power as conventional petrol-diesel. After extracting oil from these plants, the remaining cake  is used for cooking, composting, and mixing in animal feed.

Specific properties of bio-diesel are given below:

1. Sulfur / carbon dioxide is not emitted by ignition of bio-diesel.

2. It is non-toxic and non-polluted.

3. It is bio-degradable and environment friendly.

4. Hydrocarbons do not occur without burning.

Geothermal Plant

6.Geothermal energy: The heat trapped inside the surface of the Earth is called geothermal energy.

This energy is available to a depth of about 10 kilo-meter from the surface of the Earth. As we move downwards from the top surface of the earth, the temperature increases. On entering the earth, the temperature increases by 1 degree Celsius per 64 meters of depth. In this way, there is special heat under the ground. This heat emerges from the Earth's core through rocks and crevices and reaches the earth's crust. This heat is used for obtaining the energy.

The uses of geothermal energy are as follows:

1.Generation of electric power

2.Industrial process heat

3.Space heating for different buildings.

Ocean and Tidal wave

7.Ocean energy: Ocean is a source of energy.

There are two types of ocean energy:

• Ocean wave energy
• Ocean tidal energy

1.Ocean wave energy: They generate electricity by running turbines from the waves generated due to the flow of ocean water. In this way, ocean energy is converted  into electrical energy.

2.Tidal Energy: When the water rises on the beach during ocean tides, electric energy is generated by running a turbine while falling from it.

8.Biomass: It is the energy obtained from organic materials i.e. trees and animals. Animal feed and tree residuals can generate electrical energy by using this in a biomass reactor.

→It is estimated that 90% of biomass comes from trees.

The benefits of biomass energy essay is written

1. It is an indigenous source of energy 

2. Biomass combustion generates less pollution than fossil fuels.

STEP POTENTIAL AND TOUCH POTENTIAL

WHAT IS STEP POTENTIAL AND TOUCH POTENTIAL?

The knowledge of step potential and touch potential is very important.If you work in the electrical field. In this article, we will talk about step potential and touch potential in substation, transmission and distribution system.

Step potential: The step potential of sub-station and transmission, distribution line is given below:

Step potential at sub-station: At the time of earth fault, the fault current flow in earth. Then the voltage generated between the feet of the person standing on the floor of the sub station is known as step potential. Because both the feet are at different potential. So, a potential difference developed between the feet..

This voltage should be so low that the person does not get electric shock.

Step potential in transmission line and distribution line: If at the time of breakdown, transmission and distribution line falls on the earth. Then condition of the potential gradient or voltage gradient will be generated.

Potential gradient (E) = V/L

V = Voltage

L = Length

→Potential gradient: The value of the voltage will decrease as the length increases from source point.

When a person comes close to it (near the broken line on earth) then the voltage is generated between his legs, because both legs are at different voltages. Due to which the potential difference developed between the two legs. This developed voltage is known as step potential. This voltage should be so low that the person does not get electric shock.

→This step potential can be developed in the range of 10 to 15 meters from the source.

Step potential and Touch potential

Touch potential: The touch potential of sub-station and transmission, distribution line is given below:

Touch potential in sub-station: At the time of earth fault means a metallic body carrying current. Due to the earthing of the equipment. All the current will be flow in earth. But at this time some minor voltage also persists on the metallic body.

At this time if a person touch the metallic body of equipment than a minor current (due to minor voltage) will be flow from the person body to earth. Because at the time of touching the metallic body, the feet of the person presence on earth means ZERO voltage, but hand of the person is at metallic body means at minor voltage. Thus a potential difference is developed between human body and a minor voltage is flow from hand to feet. This voltage is known as touch potential. This voltage should be so low that the person does not get electric shock.

Touch potential in transmission and distribution line: If at the time of breakdown, transmission and distribution line falls on the metallic tower or pole. Due to the earthing of the tower or pole. All the current will be flow in earth. But at this time some minor voltage also persists on the tower or pole.At this time if a person touch the metallic body of tower or pole than a minor current (due to minor voltage) will be flow from the person body to earth (zero voltage). Because at the time of touching the metallic body of tower or pole, the feet of the person presence on earth means ZERO voltage, but hand of the person is at metallic body of tower or pole means at minor voltage. Thus a potential difference is developed between human body and a minor voltage is flow from hand to feet. This voltage is known as touch potential. This voltage should be so low that the person does not get electric shock.

How we can reduce the value of step potential and touch potential?

The given below point is generally used for reducing step potential and touch potential.

• By suitable earthing of sub-station equipment and tower or pole.
• In the sub-station yard earth potential and touch potential reduced by using gravel. Due to high resistance of gravel it reduces the potential gradient. Thus it reduce the step potential and touch potential.
• By the use of safety shoes and gloves.
• By the use of insulating mat in sub-station.

Why we use gravel in sub-station yard?

The reason of using gravel in substation yard is given below:

• As we have discussed earlier that the use of gravel in the sub station reduces step potential and

  

  Gravel in substation yard

  touch potential.
• This makes the earthing system suitable.
• Water does not stop in the yard during the rains means all the water goes into the ground under the gravel.
• Due to this many types of animals such as rats, snake etc. cannot make home in the yard.
• Due to this very little grass grows in the yard.